Eric Anthony Comstock

Broad and deep experience in aerospace research in multiple domains which include high enthalpy/high fidelity hypersonic computational fluid dynamics, light-particle interactions, simulations and numerical algorithm development, optical diagnostics, magnetohydrodynamics, ferrohydrodynamics, and plasma dynamics. Current research involves using analytical and computational methods to evaluate the effectiveness of novel magnetohydrodynamic plasma-breathing propulsion options and is being conducted in the Low-Gravity Science and Technology Lab at the Georgia Institute of Technology.

What I Do

NSF Graduate Research Fellowship Awarded

I am pleased to announce that I won the prestigious National Science Foundation (NSF) Graduate Research Fellowship to support my research into external plasma-breathing magnetohydrodynamic propulsion! You can read about it here.

Summer 2024 Internship at The Aerospace Corporation

I am excited to announce that I have accepted a Modeling and Simulation Graduate Internship at The Aerospace Corporation! Looking forward to everything Aerospace has to offer for summer 2024!

Current Graduate Research

External Plasma-Breathing Magnetohydrodynamic Propulsion

The hazard posed by space debris has the potential to severely dampen future space prospects. Though mitigation strategies such as satellite deorbiting and active debris removal exist, both are hindered by significant technical and economic challenges, such as the need for high Delta-V budgets. Atmosphere-breathing spacecraft propulsion has gathered attention due to its potential to avoid onboard propellant storage, but current implementations involve major architectural modifications. In this context, an external magnetohydrodynamic (MHD) propulsion system is proposed as a low-footprint alternative that avoids major spacecraft redesigns by adopting an external patch configuration.

It is found that the mass and power requirements scale linearly with the mass of the spacecraft, and that both passive and active drag components exist, and are of similar magnitude. Adopting a first-order analysis scheme, the effective specific impulse (defined as impulse generated per unit device mass) of the MHD conductive propulsion system is found to be 4-10 km/s for mission durations of 2-10 years and 10-20 km/s for mission durations of 25 years. Both active and passive uses of conductive MHD propulsion are found to be competitive against current propulsion technologies. Drawbacks of conductive MHD propulsion, such as those associated with the necessity of strong magnetic fields for operation, are also being considered.

In the near future, I plan to implement particle-in-cell (PIC) simulations as they account for low-density effects and nonlinear particle motion.

I enjoyed presenting my research at the 65th Annual Meeting of the American Physical Society Division of Plasma Physics in Denver on October 31, 2023. My presentation can be found on my "Projects" page.

Ferrohydrodynamics in the context of spherical liquid mirrors

Liquid mirror telescopes are less expensive, easier to construct, and more scalable than mirror telescopes based on solid mirrors, but must point almost directly upwards to maintain their parabolic shape. One possible way to remedy this problem is to distort the liquid mirror surface into a spherical cap, with the added symmetry allowing it to be used in telescopes pointing away from the zenith. Previous studies have discussed the possibility of using a ferrofluid-based mirror fluid and electromagnetic coils to achieve this distortion, but have not used modern optimization techniques to determine the best arrangement of coils.

This graduate research project aimed to remedy this problem by applying more recent computational models and optimization strategies to the construction of spherical liquid mirrors, both in terrestrial and lunar gravity environments.

To find the best arrangement of magnetic coils, the deviation from a spherical surface of the surface generated was found and minimized. This deviation was determined by a linear extrapolation of the combined gravitational, centrifugal, and magnetic potential function over a target spherical mirror surface.

High enthalpy/High fidelity Hypersonic CFD Modeling

This undergraduate research project involved computational modeling and optical spectrum analysis of hypersonic flows. This process started with the CFD simulation of the test apparatus - in this case, a simulation of a Mach stem in a chemically reacting, hypersonic flow. This was done by using Pointwise software to generate a mesh from the known dimensions of the test apparatus, which were then simulated using US3D software.

This simulation enabled the calculation of translational and vibrational temperatures, as well as species concentrations.

These data were inputs to the NEQAIR software, which was used to generate the optical emissions spectrum at any given point in the flow. These results were then used for comparison to experiments.

Light-Particle Interactions

This undergraduate laboratory project was the characterization of the refraction and diffraction of monochromatic directed energy through media of changing particle densities, accomplished by superimposing a laser and a rubidium supersonic jet to create a hybrid beam. This was analyzed through absorption spectroscopy to determine the magnitudes and types of interactions involved.

My Python CFD model, created in the spring of 2022, modeled a flow of argon and rubidium through the initial parts of an apparatus designed to test potential laser/particle beam coupling behavior.

A model of the section of the apparatus containing collisionless flow was added, as well as modeling the interactions of a laser with this flow. This theoretical expectation will be used to compare to the result obtained in the experiment and it will also determine carrier gases ideal for both absorption spectroscopy and analysis of near-resonance refraction.

High Power Rocketry

I have worked for several years on the practical aspect of propulsion. I earned a level 1 (M1) high-powered rocketry certification from the Tripoli Rocketry Association in 2018 and have been launching rockets ever since. Additionally, I have experience with level 2 dual-deploy rocketry systems. Please see my "Projects" page to learn more about my rocketry adventures.

Simulations and Numerical Algorithm Development

I have experience with both the finite difference method and the finite element method for hyperbolic and parabolic PDEs in arbitrary dimensional spaces, experience using them to evaluate thermal distribution and stress distribution, and experience simulating dynamic systems with high degrees of freedom using Runge-Kutta 4.

Chemistry

Undergraduate research in aerospace-related chemistry consisted of the creation of a program to generate Raman spectra for arbitrary mixtures of gases at arbitrary temperatures. This was done by simulating the quantum dynamical properties of simplified molecular systems with regards to both rotational and vibrational motion. The generated properties were used to examine their behavior in Raman scattering during hypersonic combustion.

I also have completed a graduate level course in aerothermochemistry which included several projects. These projects included chemical simulation of equilibrium hypersonic flows using data both from literature and from statistical thermodynamic calculations, as well as the use of commercial software to model both the physical and optical properties of these flows.

Additional research in organic chemistry was completed early in my undergraduate career. Please see my "Projects" page for more detail on my chemistry projects.

Space Systems

I am especially interested in contributing to any space systems project so that I may help get humanity to space which, I believe, is the only way to ensure the long-term survival of the human race.

Mentoring and Teaching Youth

I have started an outreach project through the Davidson Institute providing mentoring and teaching of high-level topics to high-potential youth who do not otherwise have access to these topics due to age restrictions. For more information about this outreach, please see my "Mentoring and Teaching" page.

Fun Facts

Favorite '80s band

Level 42

Favorite Food

Garbanzos con Espinacas

Age now

19

Total Tea Consumed in Liters

1462